ENERGY-ABSORPTION BEHAVIOR OF CARBON-FIBER-REINFORCED THERMOPLASTIC COMPOSITE TUBES

The primary objective of this work was to study the energy absorption characteristics of carbon-fiber-reinforced thermoplastic composite tubes. Composite tubes with different thermoplastic matrices-polyetheretherketone (PEEK), polyetherimide (PEI), polyimide (PI), and polyarylsulfone (PAS)-have been investigated. Fiber orientations of 0-degrees, +/- 5-degrees, +/- 10-degrees, +/- 15-degrees, +/- 20-degrees, +/- 25-degrees and +/- 30-degrees with respect to the axis of the tube were used. Among the thermoplastic tubes investigated, the carbon fiber/PEEK tubes displayed the highest specific energy absorption capability. This was attributed to the superior fracture toughness of the carbon fiber/PEEK composite material and a large number of frond splits and fractured fibers in the crush zone. The specific energy absorption capability was dependent on the fiber orientation. Efforts have been made to relate the change in specific energy to the variation of microfracture processes in the crush zone.